This invention relates to an internal combustion engine and more particularly to an improved pneumatic valve spring arrangement for such engines.
It has been recognized that the speed at which a reciprocating engine operates can be significantly increased through the use of pneumatic-type valve springs. By utilizing air pressure to close the valves rather than the more conventional coil springs, the engine can be operated at higher speeds. This is because the pneumatic spring does not have the resonant characteristics as coil springs which reduce the maximum speed at which the engine can operate. In addition, the use of pneumatic springs can provide longer life because the spring mechanism does not deteriorate with age and is not subjected to fatigue failures.
Although it is possible to operate an engine with a charged reservoir in which the air pressure is provided for the springs, a more compact, longer life assembly can be achieved if an air pump is driven off the engine for pressurizing the spring chambers. Of course, this adds to the complexity of the engine.
It is, therefore, a principal object of this invention to provide an improved and simplified air spring arrangement for an internal combustion engine.
It is a further object of this invention to provide an air compression system for an internal combustion engine that operates not only to supply air for air springs of the engine, but also air for operating or controlling other engine accessories.